Cinco de Mayo is an unofficial holiday in Hawaii, as it is in many states, but here it shares the day with another tradition. Called “Children’s Day” in Japan, most here call it “Boy’s Day,“ the 5/5 companion of “Girl’s Day” on 3/3.

A co-worker brought these tiny origami treatswith small chocolates insidefor both Boy’s Day and Girl’s Day.

In Japan, this is a national holiday, part of Golden Week celebrations. According to Wikipedia, it is also celebrated in China, Taiwan, Hong Kong, Macau, Korea and Vietnam. It has ancient roots, beginning as a seasonal festival around 600 C.E./A.D. The symbol of this day is carp – either carp banners or carp kites are popular gifts. One story is that a Chinese legend says a carp that swims upstream becomes a dragon and the way the flags blow in the wind makes it look like they are swimming.

It was known as Boy’s Day until 1948 in Japan when the government declared it to be a national holiday to “celebrate the happiness of all children and to express gratitude toward mothers.” That change apparently never made it to Hawaii, where Girl’s Day and Boy’s Day are celebrated with equal enthusiasm.

However, the name change has sparked a lively exchange today on Twitter. After several “Happy Boy’s Day” greetings were exchanged, someone noted that it is officially “Children’s Day.” A tweet then asked why Girl’s Day had been celebrated a few months ago. A female replied that perhaps every day is really Boy’s Day so they don’t need a separate celebration. As might be expected, the men on Twitter differed, saying they should enjoy holiday parity.

Amid the “Boys” and “Girls” exchanges were many Cinco de Mayo greetings, reinforcing my theory that Hawaii welcomes celebrations from every culture it encounters. I’ll give the last word to my favorite from @WatariGoro: “Happy Cinco de Boy’s Day!”